1. Field of the Invention
The present invention relates to a legacy system modernization technology for changing the existing legacy program to a program necessary for a new system, and more particularly, to a system and method that can analyze and visualize a servlet program so that the servlet program, which is a web-based program language highlighted as a dynamic web page development language, can be converted into a component-based system, and can extract business logics and generate enterprise java beans (EJB) components using the extracted business logic information.
2. Background of the Related Art
Generally, the modernization of the legacy system is required on the ground that the system environment is changed, or the manufacturing technique of software is changed for the improvement of productivity of the software. Especially, since the system is continuously changed in the current rapidly changing information technology (IT) field, the legacy system modernization is required. However, the current modernization of the legacy system has mainly been researched with respect to the Cobol, PL/1, etc., which are procedure-oriented languages, but no research has been made with respect to a web program language.
The legacy system modernization is briefly classified into redevelopment, wrapping, and transformation. The redevelopment is a method of newly developing a system having the same function as the existing system to substitute for the existing system. According to this method, the reuse is not performed at all on the software engineering side, but the existing system serves only as reference materials when the new system is developed. Also, in case that the business logic included in the existing program is important, it is difficult to authenticate whether the redevelopment of the business logic has been properly done, while in case that there is no document on the existing program, it is difficult to design a new system.
The wrapping method is a method of making the existing system be used in a new system environment by leaving the existing system as it is. According to this method, the existing program can stably be operated in the new environment.
The wrapping method has the advantages in that it is not necessary to know the structure and codes of the existing system in detail, its development cost is low, and its development term is short. However, since the programs are still operated in the existing platform, the performance that can be obtained in a new platform cannot be expected, and since the reuse can be made only as a whole through a wrapper, but cannot be partially made, the flexibility of the system is degraded.
The transformation is a method for achieving the modernization by changing the existing program to a new program through performing of an abstraction of the existing program to match the software technique of a new system. This method is ideal in the end, but since the systems of the existing and new systems are different from each other, its implementation may be difficult or impossible.
The present invention relates to the servlet program analysis, business logic extraction and EJB component generation required for the modernization of the legacy system with respect to the servlet program.
As a prior patent relating to the present invention, U.S. Pat. No. 6,389,588 “Method and system of business rule extraction from existing applications for integration into new application” discloses generation of a new application (C++, Java, Visual Basic) by extracting the business logic from the existing applications (procedure-oriented language: Cobol, PL/1, C).
Also, U.S. Pat. No. 5,960,200 “System to transition an enterprise to a distributed infrastructure” discloses a system for automatically converting source applications that operate in a two-tiered client/server system into a target application having a multi-tiered client/server structure.
Also, Korean Patent Laid-open No. 2001-96859 “Method of converting existing systems into a system useable on webs” discloses a method for solving problems generated when converting a system that does not match the existing webs or window environment into a system useable on webs, and an intellectual conversion method that can use the characteristics on the webs and remove unnecessary functions.
As described above, according to the prior art methods and systems, the modernization of the legacy system has mainly been researched with respect to the Cobol, PL/1, etc., which are the procedure-oriented languages, but no research has been made with respect to the web program language, and especially to the servlet. That is, the servlet program has the problems in that it is difficult to perform a re-abstraction of the servlet program at reverse engineering stages due to the flexibility of java languages and the construction of multi-languages, and it is impossible to reuse the servlet program since it is difficult to extract the components due to the disordered existence of the user interface for constructing a web page and the business logic.